Semiconductor device and manufacturing method of semiconductor device

ABSTRACT

A semiconductor device has a semiconductor substrate having a first surface and a second surface, a through electrode penetrating through the semiconductor substrate and having a protrusion protruding from the second surface, and an insulation layer on the second surface, which covers the side surface of the protrusion, has an opening through which to expose the end surface of the protrusion, and has a thickness greater than the length of the protrusion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2013-85851, filed on Apr. 16, 2013, the entire contents of which are incorporated herein by reference.

FIELD

The present invention relates to a semiconductor device and a manufacturing method of a semiconductor device.

BACKGROUND

Conventionally, a semiconductor device in which a plurality of semiconductor substrates having an element layer is laminated is used.

In order to increase speed, reduce power consumption, etc., of an electronic device, a three-dimensional packaging technique for laminating a plurality of semiconductor substrates having an element layer for accommodating the semiconductor substrates in one package has been proposed.

In the three-dimensional packaging technique, an electrode that penetrates through a semiconductor substrate is used in order to electrically connect semiconductor substrates to be laminated.

FIG. 1 is a diagram depicting a conventional semiconductor device.

A semiconductor device 101 is formed by laminating a first semiconductor substrate 11 having a first element layer 12 and a second semiconductor substrate 31 having a second element layer 32. The first element layer 12 and the second element layer 32 are electrically connected via through electrodes 120 a and 120 b penetrating through the first semiconductor substrate 11, bumps 42 a and 42 b, etc.

The first semiconductor substrate 11 has a first surface 11 a on which the first element layer 12 is formed and a second surface 11 b on the opposite side of the first surface 11 a. The through electrodes 120 a and 120 b penetrate through the first semiconductor substrate 11 from the first surface 11 a toward the second surface 11 b and part thereof protrudes from the second surface 11 b. The side surfaces of the through electrodes 120 a and 120 b are coated with barrier layers 23 a and 23 b and electrode insulation layers 24 a and 24 b.

On the second surface 11 b of the first semiconductor substrate 11, a first insulation layer 114 is laminated so as to embed the side surfaces of the through electrodes 120 a and 120 b. The first insulation layer 114 has openings 117 a and 117 b through which the through electrodes 120 a and 120 b are exposed. End surfaces 121 a and 121 b on the side of the second surface 11 b of the through electrodes 120 a and 120 b are exposed through the openings 117 a and 117 b.

The thickness of the first insulation layer 114 is less than the length of the portions of the through electrodes 120 a and 120 protruding from the second surface 11 b. The thickness of the portion of the first insulation layer 114 between the through electrode 120 a and the through electrode 120 b is less than that of the portions covering the side surfaces of the through electrodes 120 a and 120 b.

On the first element layer 12 of the first semiconductor substrate 11, a first wire layer 13 is laminated. To the end parts on the side of the first surface 11 a in the lengthwise direction of the through electrodes 120 a and 120 b, contacts 22 a and 22 b arranged within the first wire layer 13 are connected. The through electrodes 120 a and 120 b are electrically connected with the first element layer 12 via the contacts 22 a and 22 b. On the contacts 22 a and 22 b, bumps, not depicted, are arranged.

On the second element layer 32 of the second semiconductor substrate 31, a second wire layer 33 is laminated. On the second wire layer 33, a second insulation layer 34 is laminated.

Within the second wire layer 33, contacts 40 a and 40 b electrically connected to the second element layer 32 are arranged. On the contacts 40 a and 40 b, pads 41 a and 41 b are arranged. On the pads 41 a and 41 b, the bumps 42 a and 42 b are arranged.

Part of the pads 41 a and 41 b and the bumps 42 a and 42 b is embedded within the second insulation layer 34.

The end surfaces 121 a and 121 b on the side of the second surface 11 b of the through electrodes 120 a and 120 b are in contact with the bumps 42 a and 42 b.

Between the first insulation layer 114 and the second insulation layer 34, a filler layer 15 is filled in so as to embed the bumps 42 a and 42 b.

The first element layer 12 on the first semiconductor substrate 11 and the second element layer 32 on the second semiconductor substrate 31 are electrically connected via the contacts 22 a and 22 b, the through electrodes 120 a and 120 b, the bumps 42 a and 42 b, the pads 41 a and 41 b, and the contacts 40 a and 40 b.

Japanese Laid-open Patent Publication No. 2005-12024

As described above, the through electrode 120 a protrudes from the second surface 11 b and the length of the protruding portion is greater than the thickness of the first insulation layer 114. Consequently, when the bump 42 a and the through electrode 120 a are joined, there is a case where a part 42 c of the molten bump 42 a flows out to the lateral side of the through electrode 120 a. If the electric conductor forming the bump 42 a extends onto the first insulation layer 114, there is a possibility that a current leak path is formed.

As described above, with the conventional three-dimensional packaging technique of a semiconductor device, there is a possibility that a failure may occur in joining of the bump and the through electrode.

SUMMARY

According to an aspect of the embodiment, a semiconductor device disclosed in the present specification includes: a semiconductor substrate having a first surface and a second surface; a through electrode penetrating through the semiconductor substrate and having a protrusion protruding from the second surface; and an insulation layer on the second surface, which covers the side surface of the protrusion, has an opening through which to expose the end surface of the protrusion, and has a thickness greater than the length of the protrusion.

According to an aspect of the embodiment, a semiconductor device disclosed in the present specification includes: a first semiconductor substrate having a first surface and a second surface; a through electrode penetrating through the first semiconductor substrate and having a protrusion protruding from the second surface; an insulation layer on the second surface, which covers the side surface of the protrusion, has an opening through which to expose the end surface of the protrusion, and has a thickness greater than the length of the protrusion; and a second semiconductor substrate having a bump, and the second semiconductor substrate is laminated on the first semiconductor substrate so that the bump comes into contact with the end surface.

According to an aspect of the embodiment, a manufacturing method of a semiconductor device disclosed in the present specification includes: forming an electrically conductive part extending from a first surface of the semiconductor substrate toward the side of a third surface side up to part of the way; forming a protrusion by forming a second surface by processing the semiconductor substrate from the side of the third surface to reduce the thickness of the semiconductor substrate and by protruding part of the electrically conductive part from the second surface; covering the protrusion by forming an insulation layer having a thickness greater than the length of the protrusion on the second surface; and forming an opening in the insulation layer, through which to expose the end surface of the protrusion, by reducing the thickness of the insulation layer and also processing the insulation layer and the protrusion so that the length of the protrusion becomes less than the thickness of the insulation layer.

The object and advantages of the embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram depicting a conventional semiconductor device.

FIG. 2 is a diagram depicting an embodiment of a semiconductor device disclosed in the present specification.

FIG. 3 is a diagram depicting a process (part 1) of a first embodiment of a manufacturing method of a semiconductor device disclosed in the present specification.

FIG. 4 is a diagram depicting the process (part 2) of the first embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

FIG. 5 is a diagram depicting the process (part 3) of the first embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

FIG. 6 is a diagram depicting the process (part 4) of the first embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

FIG. 7 is a diagram depicting the process (part 5) of the first embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

FIG. 8 is a diagram depicting the process (part 6) of the first embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

FIG. 9 is a diagram depicting the process (part 7) of the first embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

FIG. 10 is a diagram depicting another embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

FIG. 11 is a diagram depicting still another embodiment of the manufacturing method of the semiconductor device disclosed in the present specification.

DESCRIPTION OF EMBODIMENTS

Hereinafter, preferred embodiments of a semiconductor device disclosed in the present specification are illustrated with reference to drawings. However, the technical scope of the present invention is not limited to the embodiments and the scope encompasses the inventions described in the claims and equivalents thereof.

FIG. 2 is a diagram depicting an embodiment of a semiconductor device disclosed in the present specification.

A semiconductor device 10 of the present embodiment is formed by laminating a first semiconductor substrate 11 having a first element layer 12 and a second semiconductor substrate 31 having a second element layer 32. The first element layer 12 and the second element layer 32 are electrically connected via through electrodes 20 a and 20 b penetrating through the first semiconductor substrate 11, bumps 42 a and 42 b, etc.

The first semiconductor substrate 11 has a first surface 11 a on which the first element layer 12 is formed and a second surface 11 b on the opposite side of the first surface 11 a. The through electrodes 20 a and 20 b penetrate through the first semiconductor substrate 11 from the first surface 11 a toward the second surface 11 b and part thereof protrudes from the second surface 11 b.

The through electrodes 20 a and 20 b are formed by filling through holes penetrating through the first semiconductor substrate 11 with an electric conductor.

The side surfaces of the through electrodes 20 a and 20 b are coated with barrier layers 23 a and 23 b and electrode insulation layers 24 a and 24 b. The barrier layers 23 a and 23 b prevent the electric conductor within the through hole from diffusing into the first semiconductor substrate 11. The electrode insulation layers 24 a and 24 b electrically insulate the electric conductor within the through hole from the first semiconductor substrate 11.

On the second surface 11 b of the first semiconductor substrate 11, a first insulation layer 14 is laminated so as to embed the side surfaces of the through electrodes 20 a and 20 b. The thickness of the first insulation layer 14 is greater than the length of the portions of the through electrodes 20 a and 20 b protruding from the second surface 11 b. Further, the first insulation layer 14 has openings 17 a and 17 b through which the through electrodes 20 a and 20 b are exposed. The first insulation layer 14 protects the through electrodes 20 a and 20 b as well as electrically insulating the side surfaces of the through electrodes 20 a and 20 b from the surroundings.

End surfaces 21 a and 21 b on the side of the second surface 11 b in the lengthwise direction of the through electrodes 20 a and 20 b has a shape concave toward the side of the first surface 11 a of the first semiconductor substrate 11. The positions of the end surfaces 21 a and 21 b are nearer to the first surface 11 a than the surface of the first insulation layer 14 in the thickness direction of the first semiconductor substrate 11.

Around the openings 17 a and 17 b of the first insulation layer 14, slant parts 14 a and 14 b that slant from the surface of the first insulation layer 14 toward the end surfaces 21 a and 21 b of the through electrodes 20 a and 20 b are formed (see FIG. 2 and FIG. 8).

The end surfaces 21 a and 21 b and the slant parts 14 a and 14 b form concave parts 16 a and 16 b having a curved surface. The end surfaces of the barrier layers 23 a and 23 b and the electrode insulation layers 24 a and 24 b also form part of the concave parts 16 a and 16 b.

The bumps 42 a and 42 b have a shape that fits the curved surfaces of the concave parts 16 a and 16 b and electrically connect with the end surfaces 21 a and 21 b of the through electrodes 20 a and 20 b exposed through the openings 17 a and 17 b.

On the first element layer 12 of the first semiconductor substrate 11, a first wire layer 13 is laminated. To the end parts on the side of the first surface 11 a in the lengthwise direction of the through electrodes 20 a and 20 b, contacts 22 a and 22 b arranged within the first wire layer 13 are connected. The through electrodes 20 a and 20 b electrically connect with the first element layer 12 via the contacts 22 a and 22 b. On the contacts 22 a and 22 b, bumps, not depicted, are arranged.

On the second element layer 32 of the second semiconductor substrate 31, a second wire layer 33 is laminated. On the second wire layer 33, a second insulation layer 34 is laminated.

Within the second wire layer 33, contacts 40 a and 40 b electrically connected with the second element layer 32 are arranged. On the contacts 40 a and 40 b, electrically conductive pads 41 a and 41 b are arranged. On the pads 41 a and 41 b, the bumps 42 a and 42 b are arranged. It may also be possible to arrange a seed layer that improves the electrical connection between the contacts 40 a and 40 b and the pads 41 a and 41 b in between. Similarly, It may also be possible to arrange a seed layer that improves the electrical connection between the pads 41 a and 41 b and the bumps 42 a and 42 b in between.

Part of the pads 41 a and 41 b and the bumps 42 a and 42 b is embedded within the second insulation layer 34.

Between the first insulation layer 14 and the second insulation layer 34, a filler layer 15 is filled in so as to embed the bumps 42 a and 42 b. The filler layer 15 protects the bumps 42 a and 42 b as well as electrically insulating the bumps 42 a and 42 b from the surroundings.

The first element layer 12 on the first semiconductor substrate 11 and the second element layer 32 on the second semiconductor substrate 31 are electrically connected via the contacts 22 a and 22 b, the through electrodes 20 a and 20 b, the bumps 42 a and 42 b, the pads 41 a and 41 b, and the contacts 40 a and 40 b.

The dimensions of each component of the semiconductor device 10 of the present embodiment may be set appropriately. For example, a diameter L1 of the through electrodes 20 a and 20 b may be set to 5 to 10 μm. Preferably, a diameter L2 of the concave parts 16 a and 16 b is 15 μm or less. Preferably, a depth L3 of the concave parts 16 a and 16 b is 5 μm or less. A diameter L4 of the bumps 42 a and 42 b may be set to 10 to 30 μm. Preferably, a thickness L5 of the first insulation layer 14 is 10 μm or less. A thickness L6 of the filler layer 15 may be set to 5 to 10 μm.

The forming material of each component of the semiconductor device 10 of the present embodiment may be selected appropriately. As the forming material of the first semiconductor substrate 11 and the second semiconductor substrate 31, for example, a silicon substrate may be used. As the forming material of the through electrodes 20 a and 20 b, for example, copper or aluminum may be used. As the forming material of the first insulation layer 14, for example, resin, such as polyimide resin and epoxy resin, or the Low-k material, such as SiOC, may be used. As the forming material of the second insulation layer 34, for example, silicon oxide or silicon nitride may be used. As the forming material of the barrier layers 23 a and 23 b, for example, Ta, TaN, and TiN may be used. As the forming material of the electrode insulation layers 24 a and 24 b, for example, TEOS may be used.

The semiconductor device 10 in the example depicted in FIG. 2 has two through electrodes penetrating through the first semiconductor substrate, however, the semiconductor device 10 may have one or three or more through electrodes.

Next, a first embodiment of a manufacturing method of the semiconductor device of the present embodiment described above is illustrated below with reference to the drawings.

First, as depicted in FIG. 3, the first semiconductor substrate 11 having the first surface 11 a on which the first element layer 12 is formed and the second surface 11 b on the opposite side of the first surface 11 a is prepared. Then, after holes extending from the first surface 11 a of the first semiconductor substrate 11 toward the side of the second surface 11 b up to part of the way are formed, the electrode insulation layers 24 a and 24 b and the barrier layers 23 a and 23 b are formed in order on the inner walls of the holes. Then, the insides of the holes are filled with an electric conductor and thus electrically conductive layers 60 a and 60 b are formed. In the present embodiment, copper is used as the electric conductor.

Then, the contacts 22 a and 22 b and the first wire layer 13 that electrically connect the electrically conductive layers 60 a and 60 b and the first element layer 12 are formed on the first element layer 12. Further, bumps, not depicted, are formed on the contacts 22 a and 22 b. Then, the contacts 22 a and 22 b on which the bumps, not depicted, are formed and the first wire layer 13 are bonded onto a support substrate 50 via an adhesive layer 51 in an attachable/detachable manner. As the support substrate 50, for example, a silicon substrate or a glass plate may be used.

Next, as depicted in FIG. 4, the first semiconductor substrate 11 is processed from the side of the second surface 11 b by reducing the thickness of the first semiconductor substrate 11 so that the second surface 11 b comes closer to the first surface 11 a. As the processing method of the first semiconductor substrate 11, for example, it is possible to use the grinding method, such as back grinding, the polishing method, such as chemical mechanical polishing (CMP), etc. The amount of reduction in thickness by processing the first semiconductor substrate 11 may be set appropriately from the viewpoint of the degree of flatness, etc., of the second surface 11 b.

Next, as depicted in FIG. 5, the thickness of the first semiconductor substrate 11 is further reduced by etching the side of the second surface 11 b of the first semiconductor substrate 11 so as to protrude part of the electrically conductive layers 60 a and 60 b from the second surface 11 b. As the etching method, wet etching or dry etching may be used. Preferably, the etching method enables selection of etching having an etching rate for the first semiconductor substrate 11 higher than that for the electrode insulation layers 24 a and 24 b. The electrically conductive layers 60 a and 60 b are maintained in the state of being coated with the electrode insulation layers 24 a and 24 b and the barrier layers 23 a and 23 b.

Next, as depicted in FIG. 6, the first insulation layer 14 whose thickness is greater than the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b is formed on the second surface 11 b. The first insulation layer 14 is formed so as to embed the side surfaces and the end surfaces of the electrically conductive layers 60 a and 60 b, on which the electrode insulation layers 24 a and 24 b and the barrier layers 23 a and 23 b are formed. The first insulation layer 14 is formed so that the thickness of the portion of the first insulation layer 14 between the electrically conductive layer 60 a and the electrically conductive layer 60 b is also greater than the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b.

As the method for forming the first insulation layer 14, for example, it is possible to use the application method, such as spin coat, or the vapor deposition method, such as CVD. In the present embodiment, the first insulation layer 14 is formed by the Low-k material by using the spin coat method.

Next, as depicted in FIG. 7, the first insulation layer 14 is processed so that the thickness of the first insulation layer 14 is reduced until the electrically conductive layers 60 a and 60 b are exposed.

As the processing method of the first insulation layer 14, it is possible to use, for example, the grinding method, such as single point tool grinding, and the polishing method, such as chemical mechanical polishing (CMP). As the processing method, it is preferable to select a processing method in accordance with the forming material of the first insulation layer 14 from the viewpoint of reducing the tact time of the process. The processing rate is the grinding rate or the polishing rate of the first insulation layer 14.

In the present embodiment, as the processing method of the first insulation layer 14, CMP is selected, which has a processing rate equal to or higher than a predetermined rate for the Low-k material forming the first insulation layer 14. As the slurry used in CMP, it is preferable to use slurry having a polishing rate equal to or higher than a predetermined rate for the barrier layers 23 a and 23 b from the viewpoint of reducing the tact time of the process. Preferably, such slurry includes, as its component, abrasive grains, such as colloidal silica, or an organic acid, such as a chelating agent, a citric acid, and an oxalic acid, or an additive, such as ammonia water, potassium hydroxide, and a hydrogen peroxide solution, or a non-ionic detergent, such as polyethylene glycol.

In the example depicted in FIG. 7, the first insulation layer 14 is processed so that the electrode insulation layers 24 a and 24 b and the barrier layers 23 a and 23 b are removed and the end surfaces of the electrically conductive layers 60 a and 60 b are exposed at the same level as the first insulation layer 14. The first insulation layer 14 may be processed so that part of the end parts of the electrically conductive layers 60 a and 60 b is polished. Further, the first insulation layer 14 may be processed so that the barrier layers 23 a and 23 b, or the electrode insulation layers 24 a and 24 b, or the first insulation layer 14 is left on the end surfaces of the electrically conductive layers 60 a and 60 b. In this case, the barrier layers 23 a and 23 b covering the end surfaces of the electrically conductive layers 60 a and 60 b or the first insulation layer 14 is removed in the next process.

Next, as depicted in FIG. 8, the electrically conductive layers 60 a and 60 b and the first insulation layer 14 are processed so that the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b becomes less than the thickness of the first insulation layer 14. When the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b is less than the thickness of the first insulation layer 14, the first insulation layer 14 is no longer needs to be processed.

As the processing method of the electrically conductive layers 60 a and 60 b and the first insulation layer 14, it is possible to use the polishing method, such as chemical mechanical polishing (CMP), or the etching method, such as wet etching and dry etching. As the processing method, one having a processing rate for the electrically conductive layers 60 a and 60 b higher than that for the first insulation layer 14 is preferable from the viewpoint of making the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b less than the thickness of the first insulation layer 14. The processing rate means the polishing rate or the etching rate.

In the present embodiment, as described above, the electrically conductive layers 60 a and 60 b are formed by copper, and therefore, as the processing method, CMP the same as that in the process depicted in FIG. 7 is selected. The slurry used in the process depicted in FIG. 7 has a polishing rate equal to or higher than a predetermined rate for copper, and therefore, the same slurry as the slurry in the process depicted in FIG. 7 is used in CMP.

Consequently, in the present embodiment, the processes depicted in FIG. 7 and FIG. 8 are performed using CMP, the same processing method, and the same slurry. That is, it is possible to perform the processes depicted in FIG. 7 and FIG. 8 in one process.

In the manner such as this, in the first insulation layer 14, the openings 17 a and 17 b through which the surfaces of the electrically conductive layers 60 a and 60 b are exposed are formed.

The electrically conductive layers 60 a and 60 b are processed so that the surfaces of the electrically conductive layers 60 a and 60 b exposed through the openings 17 a and 17 b of the first insulation layer 14 become concave toward the side of the first surface 11 a of the first semiconductor substrate 11. The reason is that CMP is the isotropic polishing method. Specifically, the reason is that the centers of the exposed surfaces of the electrically conductive layers 60 a and 60 b are supplied with a larger amount of etching component in the slurry than that supplied to the periphery of the surfaces. Because of this, on the exposed surfaces of the electrically conductive layers 60 a and 60 b, the polishing rate of the centers of the surfaces is higher than that of the periphery of the surfaces. Consequently, the end surfaces 21 a and 21 b on the side of the second surface 11 b in the lengthwise direction of the electrically conductive layers 60 a and 60 b are polished into the shape concave toward the side of the first surface 11 a of the first semiconductor substrate 11.

In the manner such as this, the through electrodes 20 a and 20 b penetrating through the first semiconductor substrate 11 are formed.

Further, the first insulation layer 14 is processed so that the periphery of the openings 17 a and 17 b slants toward the electrically conductive layers 60 a and 60 b, and thus the slant parts 14 a and 14 b are formed. The reason that the slant parts 14 a and 14 b are formed is the same as that the end surfaces 21 a and 21 b having the above-described concave shape are formed.

In this manner, the concave parts 16 a and 16 b having a curved surface are formed by the end surfaces 21 a and 21 b and the slant parts 14 a and 14 b. It is preferable for the shape of the curved surfaces of the concave parts 16 a and 16 b to agree with the radius of curvature determined based on the surface tension of the bumps 42 a and 42 b in the molten state when laminating the second semiconductor substrate 31 on the first semiconductor substrate 11 from the viewpoint of forming an excellent electrical connection state of the bumps and the end surfaces.

Next, as depicted in FIG. 9, the second semiconductor substrate 31 having the bumps 42 a and 42 b heated and in the molten state is laminated on the first semiconductor substrate 11 so that the bumps 42 a and 42 b come into contact with the end surfaces 21 a and 21 b of the through electrodes 20 a and 20 b exposed in the openings 17 a and 17 b. The second semiconductor substrate 31 is pressed onto the first semiconductor substrate 11 so that the bumps 42 a and 42 b in the molten state are inserted into the concave parts 16 a and 16 b. Then, the cooled bumps 42 a and 42 b are electrically joined to the end surfaces 21 a and 21 b of the through electrodes 20 a and 20 b.

Then, the space between the first insulation layer 14 and the second insulation layer 34 is filled with a filler so as to embed the bumps 42 a and 42 b, and thus a filler layer, not depicted, is formed. Then, the adhesive layer 51 is detached from the contacts 22 a and 22 b on which the bumps are formed and the first wire layer 13, and thus the semiconductor device depicted in FIG. 2 is formed.

According to the first embodiment of the manufacturing method of the semiconductor device described above, it is possible to prevent a bad joint between the bump and the through electrode.

Specifically, the end surfaces 21 a and 21 b of the through electrodes 20 a and 20 b are within the concave parts 16 a and 16 b, and therefore, the bumps 42 a and 42 b in the molten state are suppressed from flowing onto the first insulation layer 14. Further, the contact area between the end surfaces 21 a and 21 b of the through electrodes 20 a and 20 b and the bumps 42 a and 42 b in the molten state is large compared to that in the case where the end surface of the through electrode is flat, and therefore, it is possible to reduce the contact resistance.

Furthermore, according to the first embodiment of the manufacturing method of the semiconductor device of the present embodiment, it is possible to solve the conventional problems illustrated below.

In the conventional example depicted in FIG. 1, there is a case where the first insulation layer 114 is formed by the spin coat method and the portion of the first insulation layer 114 formed on the through electrodes 120 a and 120 b protruding from the second surface 11 b of the first semiconductor substrate 11 is removed by dry etching. In the case where there are a part where the density of the through electrode is high and a part where the density is low, at the part where the density is low, the first insulation layer 114 that is applied is formed so as to have a thickness less than that at the part where the density is high due to a difference in the magnitude of the influence of surface tension. Because of this, there is a case where the part where the first insulation layer 114 is thin is removed at the time of etching, and therefore, the first semiconductor substrate 11 is exposed.

On the other hand, according to the first embodiment of the manufacturing method of the semiconductor device of the present embodiment, it is possible to prevent the problem such as this from occurring.

Further, in the conventional example depicted in FIG. 1, there is a case where the first insulation layer 114 is formed by the spin coat method and the portion of the first insulation layer 114 formed on the through electrodes 120 a and 120 b protruding from the second surface 11 b of the first semiconductor substrate 11 is removed by CMP. There is a case where the through electrode protruding from the second surface 11 b of the first semiconductor substrate 11 is caused to fall due to CMP.

On the other hand, according to the first embodiment of the manufacturing method of the semiconductor device of the present embodiment, it is possible to prevent the problem such as this from occurring.

Further, in the conventional example, there is a case where the first insulation layer 114 is formed by the CVD method and the portion of the first insulation layer 114 formed on the through electrodes 120 a and 120 b protruding from the second surface 11 b of the first semiconductor substrate 11 is removed by dry etching. At this time, in order to protect the first insulation layer 114 laminated on the first semiconductor substrate 11, a resist layer is formed before dry etching. Because of this, in the case where the first insulation layer 114 is formed by the CVD method, the process to form the resist layer is further provided.

On the other hand, according to the first embodiment of the manufacturing method of the semiconductor device of the present embodiment, the process such as this is obviated.

Next, other embodiments of the manufacturing method of the semiconductor device described above are illustrated below with reference to the drawings. To the other embodiments not illustrated in particular, the illustration described in detail in the first embodiment described above can be applied appropriately. The same symbols are attached to the same components.

Second to fourth embodiments of the manufacturing method of the semiconductor device illustrated below differ from the first embodiment described above in the processes in FIG. 6 to FIG. 8. The processes other than those in FIG. 6 to FIG. 8 are the same as those in the first embodiment described above, and therefore, for the second to fourth embodiments, the processes in FIG. 6 to FIG. 8 are illustrated.

For the second to fourth embodiments of the manufacturing method of the semiconductor device, an example in which the forming material of the first insulation layer 14 is different from that in the first embodiment described above, or an example in which the processing method of the first insulation layer 14 or the electrically conductive layers 60 a and 60 b is different is illustrated.

First, the second embodiment of the manufacturing method of the semiconductor device is illustrated below with reference to FIG. 6 to FIG. 8.

First, as depicted in FIG. 6, the first insulation layer 14 whose thickness is greater than the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b is formed on the second surface 11 b. In the present embodiment, as in the first embodiment, the first insulation layer 14 is formed by the Low-k material by using the spin coat method.

Next, as depicted in FIG. 7, the first insulation layer 14 is processed so that the thickness of the first insulation layer 14 is reduced until the electrically conductive layers 60 a and 60 b are exposed. In the present embodiment, as the processing method of the first insulation layer 14, as in the first embodiment, CMP is selected, which has a processing rate equal to or higher than a predetermined rate for the Low-k material forming the first insulation layer 14. Specifically, as the slurry used in CMP, the same slurry as that in the first embodiment is used. In the process depicted in FIG. 7, the electrode insulation layers 24 a and 24 b and the barrier layers 23 a and 23 b are removed by polishing and the end surfaces of the electrically conductive layers 60 a and 60 b are exposed.

Next, as depicted in FIG. 8, the electrically conductive layers 60 a and 60 b and the first insulation layer 14 are processed so that the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b becomes less than the thickness of the first insulation layer 14. In the present embodiment, as the processing method of the electrically conductive layers 60 a and 60 b and the first insulation layer 14, CMP is selected, which has a processing rate equal to or higher than a predetermined rate for copper forming the electrically conductive layers 60 a and 60 b. As the slurry used in CMP, it is preferable to use the slurry having a polishing rate equal to or higher than a predetermined rate for the electrically conductive layers 60 a and 60 b from the viewpoint of reducing the tact time of the process. Preferably, the slurry such as this includes abrasive grains, such as colloidal silica, or an organic acid, such as a citric acid, an oxalic acid, and a malic acid, or an amino acid, such as glycine, an additive, such as ammonia water, a hydrogen peroxide solution, a nitric acid, and benzotriazole (BTA).

In the first embodiment of the manufacturing method of the semiconductor device described above, the slurry used in CMP to polish the electrically conductive layers 60 a and 60 b has a polishing rate equal to or higher than a predetermined rate for the barrier layers 23 a and 23 b. In the process depicted in FIG. 8 of the present embodiment, it is sufficient to polish the electrically conductive layers 60 a and 60 b whose copper end surfaces are exposed, and therefore, there are no restrictions in particular on the polishing rate for the barrier layers 23 a and 23 b. Consequently, the slurry used in CMP to polish the electrically conductive layers 60 a and 60 b may have a low polishing rate for the barrier layers 23 a and 23 b. Because of this, in the present embodiment, as the slurry used in CMP, slurry having a polishing rate equal to or higher than a predetermined rate for copper forming the electrically conductive layers 60 a and 60 b is used.

In the present embodiment, the slurry used in CMP in the process depicted in FIG. 7 is different from the slurry used in CMP in the process depicted in FIG. 8.

Next, a third embodiment of the manufacturing method of the semiconductor device is illustrated below with reference to FIG. 6 to FIG. 8.

First, as depicted in FIG. 6, the first insulation layer 14 whose thickness is greater than the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b is formed on the second surface 11 b. In the present embodiment, the first insulation layer 14 is formed by resin, such as polyimide resin and epoxy resin, by using the spin coat method.

Next, as depicted in FIG. 7, the first insulation layer 14 is processed so that the thickness of the first insulation layer 14 is reduced until the electrically conductive layers 60 a and 60 b are exposed. In the present embodiment, as the processing method of the first insulation layer 14, single point tool grinding having a processing rate equal to or higher than a predetermined rate for the resin forming the first insulation layer 14 is selected. The single point tool grinding is a grinding method for grinding the surface of a rotating semiconductor substrate using a reciprocating blade. For the resin forming the first insulation layer 14, the polishing rate of CMP is low, and therefore, the grinding method having a high processing rate for resin is selected. In the process depicted in FIG. 7, the electrode insulation layers 24 a and 24 b and the barrier layers 23 a and 23 b are removed by grinding and the end surfaces of the electrically conductive layers 60 a and 60 b are exposed.

Next, as depicted in FIG. 8, the electrically conductive layers 60 a and 60 b and the first insulation layer 14 are processed so that the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b becomes less than the thickness of the first insulation layer 14. In the present embodiment, as the processing method of the electrically conductive layers 60 a and 60 b and the first insulation layer 14, CMP is selected, which has a processing rate equal to or higher than a predetermined rate for copper forming the electrically conductive layers 60 a and 60 b. As the slurry used in CMP, it is preferable to use the slurry having a polishing rate equal to or higher than a predetermined rate for the electrically conductive layers 60 a and 60 b from the viewpoint of reducing the tact time of the process. Preferably, the slurry such as this includes abrasive grains, such as colloidal silica, or an organic acid, such as a citric acid, an oxalic acid, and a malic acid, or an amino acid, such as glycine, an additive, such as ammonia water, a hydrogen peroxide solution, a nitric acid, and benzotriazole (BTA).

In the first embodiment of the manufacturing method of the semiconductor device described above, the slurry used in CMP to polish the electrically conductive layers 60 a and 60 b has a polishing rate equal to or higher than a predetermined rate for the barrier layers 23 a and 23 b. In the process depicted in FIG. 8 of the present embodiment, it is sufficient to polish the electrically conductive layers 60 a and 60 b whose copper end surfaces are exposed, and therefore, there are no restrictions in particular on the polishing rate for the barrier layers 23 a and 23 b. Consequently, the slurry used in CMP to polish the electrically conductive layers 60 a and 60 b may have a low polishing rate for the barrier layers 23 a and 23 b. Because of this, in the present embodiment, as the slurry used in CMP, slurry having a polishing rate equal to or higher than a predetermined rate for copper forming the electrically conductive layers 60 a and 60 b is used.

As described above, in the present embodiment, as the processing method in the process depicted in FIG. 7, the grinding method is used and as the processing method in the process depicted in FIG. 8, the polishing method is used, and therefore, the processing methods in both the processes are different.

Next, the fourth embodiment of the manufacturing method of the semiconductor device is illustrated below with reference to FIG. 6 to FIG. 8.

First, as depicted in FIG. 6, the first insulation layer 14 whose thickness is greater than the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b is formed on the second surface 11 b. In the present embodiment, the first insulation layer 14 is formed by resin, such as polyimide resin and epoxy resin, by using the spin coat method.

Next, as depicted in FIG. 7, the first insulation layer 14 is processed so that the thickness of the first insulation layer 14 is reduced until the electrically conductive layers 60 a and 60 b are exposed. In the present embodiment, as the processing method of the first insulation layer 14, single point tool grinding having a processing rate equal to or higher than a predetermined rate for the resin forming the first insulation layer 14 is selected. In the process depicted in FIG. 7, the electrode insulation layers 24 a and 24 b and the barrier layers 23 a and 23 b are removed by grinding and the end surfaces of the electrically conductive layers 60 a and 60 b are exposed.

Next, as depicted in FIG. 8, the electrically conductive layers 60 a and 60 b and the first insulation layer 14 are processed so that the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b becomes less than the thickness of the first insulation layer 14. In the present embodiment, as the processing method of the electrically conductive layers 60 a and 60 b and the first insulation layer 14, wet etching is selected, which has a processing rate equal to or higher than a predetermined rate for copper forming the electrically conductive layers 60 a and 60 b. In wet etching, it is preferable to use an etching solution having an etching rate equal to or higher than a predetermined rate for the electrically conductive layers 60 a and 60 b from the viewpoint of reducing the tact time of the process. As the etching solution such as this, it is possible to use, for example, a hydrogen peroxide solution, a hydrofluoric acid, a nitric acid, a sulfuric acid, or a mixed solution thereof.

In the present invention, it is possible to appropriately change the semiconductor device and the manufacturing method of the semiconductor device of the embodiments described above as long as the gist of the present invention is not deviated. Further, it is also possible to appropriately apply components in an embodiment to the other embodiments.

In the process in FIG. 8 of the embodiment of the manufacturing method of the semiconductor device described above, the concave parts 16 a and 16 b have the curved shape concave toward the side of the first surface 11 a of the first semiconductor substrate 11. The concave parts 16 a and 16 b may have another shape as long as the length of the portions of the electrically conductive layers 60 a and 60 b protruding from the second surface 11 b becomes less than the thickness of the first insulation layer 14.

For example, as depicted in FIG. 10, the concave parts 16 a and 16 b may be formed by the end surfaces 21 a and 21 b having flat surfaces and vertical parts 18 a and 18 b having an orientation vertical to the end surfaces 21 a and 21 b. It is possible to form the end surfaces 21 a and 21 b having flat surfaces by, for example, dry etching.

Further, as depicted in FIG. 11, the concave parts 16 a and 16 b may be formed by the end surfaces 21 a and 21 b having flat surfaces and the slant parts 14 a and 14 b having an orientation inclined with respect to the end surfaces 21 a and 21 b.

All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it is to be understood that the various changes, substitutions, and alterations are possible without departing from the sprit and scope of the invention. 

What is claimed is:
 1. A semiconductor device comprising: a semiconductor substrate having a first surface and a second surface; a through electrode penetrating through the semiconductor substrate and having a protrusion protruding from the second surface; and an insulation layer on the second surface, which covers a side surface of the protrusion, has an opening through which to expose an end surface of the protrusion, and has a thickness greater than the length of the protrusion.
 2. The semiconductor device according to claim 1, wherein the end surface has a shape concave toward the first surface.
 3. The semiconductor device according to claim 1, wherein the end surface has a flat shape.
 4. The semiconductor device according to claim 1, wherein the periphery of the opening is inclined toward the protrusion.
 5. The semiconductor device according to claim 1, wherein the semiconductor substrate has an element layer on the first surface.
 6. A semiconductor device comprising: a first semiconductor substrate having a first surface and a second surface; a through electrode penetrating through the first semiconductor substrate and having a protrusion protruding from the second surface; an insulation layer on the second surface, which covers a side surface of the protrusion, has an opening through which to expose an end surface of the protrusion, and has a thickness greater than the length of the protrusion; and a second semiconductor substrate having a bump, wherein the second semiconductor substrate is laminated on the first semiconductor substrate so that the bump comes into contact with the end surface.
 7. A manufacturing method of a semiconductor device comprising: forming an electrically conductive layer extending from a first surface of a semiconductor substrate toward the side of a third surface up to part of the way; forming a protrusion by forming a second surface by processing the semiconductor substrate from the side of the third surface to reduce the thickness of the semiconductor substrate and by protruding part of the electrically conductive layer from the second surface; covering the protrusion by forming an insulation layer having a thickness greater than the length of the protrusion on the second surface; and forming an opening in the insulation layer, through which to expose an end surface of the protrusion, by reducing the thickness of the insulation layer and also processing the insulation layer and the protrusion so that the length of the protrusion becomes less than the thickness of the insulation layer.
 8. The manufacturing method of a semiconductor device according to claim 7, wherein the processing the insulation layer and the protrusion processes the protrusion so that the end surface becomes concave toward the side of the first surface of the semiconductor substrate.
 9. The manufacturing method of a semiconductor device according to claim 7, wherein the processing the insulation layer and the protrusion processes the protrusion so that the end surface becomes flat.
 10. The manufacturing method of a semiconductor device according to claim 7, wherein the processing the insulation layer and the protrusion processes the insulation layer so that the periphery of the opening inclines toward the protrusion.
 11. The manufacturing method of a semiconductor device according to claim 7, wherein the processing the insulation layer and the protrusion comprises: processing first the insulation layer so that the thickness of the insulation layer is reduced until the protrusion is exposed; and processing second the protrusion so that the length of the protrusion becomes less than the thickness of the insulation layer.
 12. The manufacturing method of a semiconductor device according to claim 11, wherein the processing first has grinding or polishing.
 13. The manufacturing method of a semiconductor device according to claim 12, wherein the polishing of the processing first uses slurry having any of abrasive grains including colloidal silica, an organic acid including a chelating agent, a citric acid, or an oxalic acid, an additive including ammonia water, potassium hydroxide, or a hydrogen peroxide solution, and a non-ionic detergent including polyethylene glycol.
 14. The manufacturing method of a semiconductor device according to claim 11, wherein the processing second has a first processing rate for the semiconductor substrate and a second processing rate for the electrically conductive layer, and the second processing rate is higher than the first processing rate.
 15. The manufacturing method of a semiconductor device according to claim 11, wherein the processing second has polishing or etching.
 16. The manufacturing method of a semiconductor device according to claim 15, wherein the polishing of the processing second uses slurry comprising any of abrasive grains including colloidal silica, an organic acid including a citric acid, an oxalic acid, or a malic acid, an amino acid including glycine, and an additive including ammonia water, a hydrogen peroxide solution, a nitric acid, or benzotriazole.
 17. The manufacturing method of a semiconductor device according to claim 15, wherein the etching of the processing second is wet etching using a hydrogen peroxide solution, a hydrofluoric acid, a nitric acid, a sulfuric acid, or a mixed solution thereof.
 18. The manufacturing method of a semiconductor device according to claim 7, wherein before the processing the electrically conductive layer, an element layer is formed on the first surface of the semiconductor substrate. 